Income Taxes - Pretax Loss and the Components of Income Tax Benefit (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Pretax Loss	$ (943)	$ (1,003)
Current
Federal	0	0
State	0	0
Current income tax benefit	0	0
Deferred
Federal	0	0
State	0	0
Total income tax expense	$ 0	$ 0